The term “air grill” is used in reference to gratings used to cover openings in the ventilation system for the purpose of supplying or exhausting air to or from a given space.
The term “security institution” is used in reference to correctional facilities, penal facilities, mental health facilities and/or any other type of facility where the persons under the care of such facility are purposely and/or lawfully isolated from the public.
Air grills used in security applications must perform above and beyond the standard inlet/outlet air grills. Specifically, such a security grill must be incapable of being disassembled to create weapons or tools, the security grill must restrict access to the ductwork beyond the grill to prevent storage of contraband material, the security grill must prevent escape or entry into the ductwork, and the security grill must virtually eliminate the occupant's ability to thread items into the air channels or passages of the diffuser for the purpose of suicide attempts.
Conventional security grills for security institutions that meet the above mentioned requirements generally comprise a body having two opposed faces, where at least one passage extends through the body between the opposed faces creating an air channel. The passageway (air channel) has at least one change in direction creating a so-called “zigzag pattern.” FIG. 1 illustrates such a conventional security grill.
The prior art security grill shown in FIG. 1 consists of a body 10 having two opposed faces 11 and 12, and a number of channels 13 extending through the body between the opposed faces. Each channel 13 has at least one change in direction defining a zigzag pattern. The zigzag pattern of each channel forms segments S1, S2, S3, and S4 which have a rectangular cross-sectional shape. The problem with conventional security grill designs is the notion that very little can be done to improve the air delivery performance and efficiency of the security grill without compromising the requirements of the air grills for security institutions as stated above.
What is required is an air grill for security institutions that would provide the security institutions with a more efficient and cost effective method of ventilating space without compromising the safety of the occupants.